FLT_IS_SYSTEM_BUFFER macro (fltkernel.h)

Article
02/22/2024

The FLT_IS_SYSTEM_BUFFER macro tests the system buffer flag in a callback data structure.

Syntax

void FLT_IS_SYSTEM_BUFFER(
   Data
);

Parameters

Data

[in] Pointer to a callback data (FLT_CALLBACK_DATA) structure.

Return value

None

Remarks

FLT_IS_SYSTEM_BUFFER returns TRUE if the system buffer flag is set in the callback data structure; FALSE otherwise.

The FLT_IS_SYSTEM_BUFFER macro checks whether the system buffer flag (FLTFL_CALLBACK_DATA_SYSTEM_BUFFER) is set in a callback data (FLT_CALLBACK_DATA) structure.

The system buffer flag is set in the callback data structure for an I/O operation if the buffer for the operation is allocated from nonpaged pool. If this flag is set, minifilter drivers can assume that the buffer is already locked down and can be accessed safely.

Note that minifilter drivers must never set the system buffer flag.

Requirements

Requirement	Value
Header	fltkernel.h